Charles b



July 2; 192s. 1,546,932

l C. B. JACOBS v PROCESS 0F EXTRACTING ALKALI METAL GYANIDB FROM MAssEscoNTAINING OTHER ALKALI METAL COMPOUNDS soLuBLE 1N WATER Filed March 11.1920 #NVEN'ron C'. Jaco/s,

Gran-.a MCHMMCOAMF par 100 grams (1,0 U

I ATToaNnY @.5

Patented July 2l, 1925.,

raison PATENT OFFlCE..

n. tracers, or WILMINGTON, DELAWARE, assit-avon To n, I. nu Pour nntuna/tonus o ooairnnv, or "automatiseren, nnnaurann, .a conronarron or:onna- Wann l-BCESS l? EXTRATENG' ALKAL METAL YANDE FRM CONTAINING[ETHER ALKALI METALL COMPOUNDSSOLUBLEN WATER.

Application iled lllalcll 11, 1920. Serial N0. 355,047.

To all whom t may concern:

Be it known that l, Gli-manos B. flacons, a citizen ot the UnitedStates, and a resident ot llllilinington, in the county et New thistleand State' of Delaware, have invented a certain new and useful Processol' Exti-acting` Alkali llletil rCyanide from li/iasses loutaiin a;Other Vi--illtali ll/lctal Compounds Flolnhle in lllater, ot which the:Following is a specilication.

This invention is in the art of nitrogen lixation an d relates morel"oarticularly to the extracting olf' nl ali metal cyanides lrorn themasses ot alkali inetalcyanide, allrali metal carbonate, etc...resulting' 'from those lixa tion ilirocesses wherein tree or elementalnitrooen, in a 'lires sta e or as a constituent of a nitrogen-hef fing'gras, is caused to coinV bine directly and at hinh temperature withcarbon and a compound oi an alkali instal, to torni an alkali metalcyanide, the cheniical reaction involved hein@l empirically ef:-ijressed by the equationstaccare-tri,zsuairwraco,

when sodium carbonate is used. Sodium carbonate, on account ot itsahundance and relatively lon7 cost, is the alkali instal conipoundusually employed in the production or alkali metal cyanide, andtherefore, tor dcniteness andto most clearly explain iny invention, lrefer inore na... icularly to sodium carbonate and cyanide; but l do not*ict niv invention to the extracting` oit sodnn cyanide.

The furnace Vproduct resulting` frein a vfixation process such as thatmentioned is not,y however, simply the allrali Vinstal cyanide desired aa product, but,i:'ather, it contains a Water soluble portion consistingof au intimate .mixture ot .the cyanide, alkali metal carbonate, alkalimetal halide, as un chlorideor fluoride, in cases Where been used asiacatalyzer, and

it h i alkali metal oxide .(l'orined by the reduction oil thecarbonate). Un treatment ot such a cyanized i'urnace product with Water,there results, in the Acase 4Where alkali halides are absent, the systemNaCN, NaZCS, H20, and Nalll-l (termed trom the oxido present); and inthe case, Where alkali halides are present, the system NaCN, NaZC/O,NaOH, Hdl, and NaCl or NalP (as the case may be).

lleretotoii'e `great ditlicultyihas been eX- perienced in the separationof alkali cyanide in a tree state from aqueous solutions, as thoseindicated. just above; for, it a cyanide solution is contaminated bysalts other than sinall quantities oit the hydroxide or carbonate et'the alkali, the recovery et the cyanide by crystallization is veryditlicult and in niost cases practically impossible (see Chemistry otCyanogeu Compounds; l l?. lllilliarns, page 302, etseq.)` Se, the coinercially gracticahle separation of the cyanide 'trein a furnaceprodnctol the character indicated has always presented an eX- noinicaland unsatisfactory in commercial practice and the solubilities 1n Waterot the cyanide, carbonate, chloride, and fluoride of sodium given in thesolubility tables ot the literature, and shown by the-curves in Figure lot the drawings, (the solubility curves all inclining roughly in thesaine direction, see Figure l) have made it appear practically hopelessto attempt the separation 01"' sodium cyanide troni mixtures with any otthe other salts, by extraction with Water.

Now l have discovered, that, as a matter oilf fact, Water can besatisfactorily and practically used to extract the cyanide troni themass and separatefit trom the other inaterials, hydissolving; thecyanide and impurities in water and then crystallizing out the cyanide,leaving! the impurities in solution; specifically. I have discoveredthat the lconcurrent solubilities ot the various materials in relativelyhot water, and in relatively cold, are such that whereas the cyanide ishighly soluble in relatively hot water and much less soluble inrelatively cold, the other compounds are less soluble in relatively hotwater than in relatively cold. I have provided a process for theextracting` of cyanide and based on this discovery, such process givingyields ot ultimate finished cyanide aniountingvto to 95% ot the cyanidepresent in the yoriginal furnace product treated, the recovered cyanidebeing trom 96 to 99% pure. This process, stated brieiiy, comprisestreating the 'furnace product with' water at a temperature oit about Q0C. or above and preferably at about 360 to 400 C. until a solutionsatura-ted with respect to cyanide is obtained, and then cooling' thesolution to desira'lily about 10 C. or below to crystallize out thecyanide. lVorking` this way, the other compounds remain in solution,and, indeed, become more soluble. as the cooling, and thecrystallization o't the cyanide proceed, and a cyanide `ot high purityis simply and easily obtained.

Also, I have discovered that small percen'tage of alkali metal hydroxidein the water increases the solubility of the cyanide at the highertemperatures and lowers it at the lower temperatures, as compared to thesolubility .of the cyanide in wat-er not containing hydroxide; while thesolubilities ot the other compounds are generally decreased somewhat atthe higher temperatures, but increase as certain of the lowerten'iperatures are approached.

One object of my invention is to provide a practical and economicalprocess tor the production ot technically pure alkali metal cyanide tromthe` cyanized :Furnace product resulting from processes in which free orelemental nitrogen is caused to combine directly with carbon and analkali metal compound to form an alkali metal cyanide.

Another object is to provide a process tor extracting with water alkalimetal cyanide `from masses containing other alkali metal compoundssoluble in water.

To these ends, and also to improve genrally on processes ot thecharacter indicated, my invention consists in the various mattershereinaiter described and claimed.

The accompanying drawings show a series of `curves giving thesolubilities. in water and as functions oiE the temperature, ot thevarious compounds to which I more particularly refer, and in thesedrawin :n

Figure l shows the individual solubility curves of sodium fluoride,sodium chloride, sodium carbonate. :and sodium cyanide: while theremaining figures show various concurrent solubility curves as followsFigure 2 shows the curves of approximate concurrent solubility oi sodiumchloride, carbonate, and cyanide in water containing' zero grams, andgrams, ot sodium hydroxide per l0() grams of water;

Figures E), and 5. show, respectively, the curves oli approximateconcurr .it solubility, in water containing;r 2 grains ol sodiumhydroxide per lll() grams ot water. of sodium carbonate and cyanide; otsodium chloride. carbonate. and cyanide; and ot sodium liu oridc,carbonate and cyanide.

The concurrent sol. ubilities shown by the curves of Figures i). to owere selected. from solubility data dcterniined by experiment. l'or thereason that they are typical ot the conditions most 'frequently met within practice. and, therefore, best illustrate the nature ol' theinvention and its practical application. The solubility determinationswere made by adding to a `given volume of water a large excess of themixed salts whose concurrent solubilities it was desired to determine,keep ingr the solution at th(` desired temperature by means ot athermostat. and in :2. stale ol' energetic agitation, and theundissolvczl salts in a state ot continual and homogenous sus-- pensionin the solution with elicicnt men chanical stirrers, until the solutionhad reached equilibriun1-which was determined by withdrawing a sample otthe solution in a weighed Lunge acid pipette trom time to time until thesolution was shown. by check analysis of two samples taken at aninterval of two hours. to contain a constant amount oi' the varioussalts. I was led to these determinations by knowledge ot the tact thatlwater showed a selective solvent action for sodium cyanide in thepresence of sodium carbonate and the 'tact that sodium cyanide depressedthe solubility o't the sodium carbonate as described in my Il. .Q PatentNo. 1.3i1232, `granted luly 29, i019.

By these determinations, I discovered. as shown by the typical curves onthe drawings. that in each particular case as tlu` teun perature rosethere was. at a certain teniperature, a maximum solubility point Vforsodium cyanide which coincided very closely with the minimum solubilitypoints ot the other salts present. and that as thc tempera-A ture wentdown. there was a` point reached when the solubility of the sodiumcyanide was proportionately lower` and the solubiliH ties ot the othersalts proportionately bijrhi er, than at the higher temperature. Thus Tfound that it is pertectly possible and wholly feasible to saturate thesolution with cyanide at the higher temperature and then obtain purecyanide by cooling the solution to the lower temperature, at which pointa larire part of the sodium cyanide crystallizes ont Vof the solution asl\Ia(ll\l.2`H. ,O7 while the other salts remain in solution. sincethen,`

lil

maoaa solulolities aregreater in a saturated eyanido solution at thelower tenuperature than they at the liirflier temperature.

Not only dld l iind this to lne true iu i'lie absence oi sodiumlijgfdroridei, ilie euri' n shown in Figures 3q il auf tliouojh showinthe `ooiieurrent soluliilities in a 2% s duim l'rvdroxide solution (theoonroutratiou most frequently ,niet with in orefftioe) l'ieiuof sui?-lieientlxy elose to the eurres sliouiiuo: tlie eonourrent soluliilitiesin the alaseuee ot sodium liiu'lroride to serre 'lor deterniiniuo; tlieoonditious tomooratui'e and ioneeutratiou 1l-'oi' extraetinofteelinioallf,7 Dure sodium @venido *Fi-oni a Jlurnaee producteontaiuino` no sodiuifn oxide ond uf'liieli oouseouontly nVields asolution eontaiuinoj no sodiuiu hydroxide, lout also li. iioun l it tolie true in tlie oi-eso ot sodium hydroxide tlirouojli a ranoe ot Porcentrati lilreli7 to lie niet with in iaraetiee. as appears direotliffrom tlio ourves Thus altliouoli it luis oreviouslv lieou lieliewed thatinorder to olitaiuoure eroi/aide troni, a mixture oontainino' sodiumoil/'anida sodium Carbonaten and sodium livflioi-ido law entraoiionWitli weiten it was first necessary to add to i'lie Wator u sudioieutamount oit sodium bioarlaoneto to een t the oolulile sodium lwdroxideDreseut into iusololilo (with resueet to a saturated sodivur'i oiuiuidsolution) sodiuru earlioue'l* and tlien to senarate the solui ou oiE s,ni fioniflo oootainino' oulv e no 'oilolo aorount sodfs'aoi carbonate'from tlie relffitiuelv insoluble residue ot sodiunfi` carbonato thefooi ,a ll liairo discovered that it uuneeef-isar);7 'lo @ouvert thesodium lwdroirido into sodium earliouate. IndeedA not only isitunneoessarv. lout nu? studi,7 of the mutual. soluliiliies ot sodium ovanideq sodium Carbonate. and also sodium oliloride and fluoride inyWriter Containin,o` various amounts of sodium hydroxide t .i 05%-, 1roto suoli eoneoutratioos would loo niet in uraotiee, sliours that tlionresenoe ot a certain amount olE sodium lwdroiride is a favorableCondition 'For seoaratinu sodiiuo cyanide from mixtures oil sodiumcyanide, sodium earl'ionato and sodium eloloride or sodium -fluoride.

The eileet o'li sodium lilvdrorzido eonoentration on tlie eoneurrentsoluliilitiee oi l'lie various salts which would nFist with it insolutions ot tlie oyaiiiirzod liuri'iaoe urodufts desorilved olioro in.tlie ease ot soo u1u .Pliliurideu shown in l? iure 2. it solutioneoutaining sodium Chloride was selected as an example of tlie eilieetoit sodium lidrorido ooneenti'ation sinee1 on aiieount ot its liio'liorsolulriliti7 suturated solutions o? tlie otlier salts solutionsooutaininoj sodiuiu elilorirle i'nio'lit iefisoualil lie esueeted liomore fliliioult sami-at@ o sodium omni from tlnin solutions ooi inisoflium oride and sodunn oarloouate` or only soduui carbonate.

in inspection of tloe curves ot lligrure f2 sliou's that with aConcentration of 5% of sodium lijy'droxiaje, more sodium. Cyanide andless sodium carbonate and sodium chloride are held in solution at thehigher enlperan tutes then is the ease 'Where the eonoentration oil"sodium hydroxide in the solution is O. lilllule if tlle solution laocooled to say 1.00 C. 'Wlueli temperature a large filo it is quiteapparent that certain eoneeutraiion el? sodium hydroxide is a favoralileoo'oditiou tor the extraction o'lz sodium orauide 'trein eyanizedfurnace products lijif liis process since larger proportion oi fl 'dethat exists in the soluer ien'lueratures will loe olitained lij*crystallization when the solutions we eooled to the lower temperatures.'llhese saine conditions prevail with solutions in sfliieli ilie allmlilia/lido sodium fluoride or there :illmli halides are absent entirely.

In the application ot tlie alim/'e soluliilitfy data to oraetiee iu tlieextraction and senaretiou oi sodium ojfanide from otlier sodiumeomoouuds existing); with it in oyanized furuooe nroduet a'tter ananalysis of the 'lino nace oroduet to determine its oomnositiou andrelative Concentration oilI the various ooutoined Wolter soluble salts7an insneotion ot' tlie soluloiliti7 eurves slioiin in lFio-ures to 5,dependino1 ou Whether the 'furnace z\.iofli1.el iu eddition to sodiumcyanide, oontaius sodium carbonate alone or accomuanied lui sodium'eliloride or sodium fluorido, will sliow tlie enueroture at Wllioli:fio leoeli or extract the turnaee product in question and tlie amounto'l'u Water to use in order to obtain approximately tlie maximum funouutoli sodium Cyanide (and ineideutall7;'Y l'lie minimum amounts oiE tileother coin- Voundsiv in tlie resulting' solution iu order to olitoiosubstantially pure sodium cyanide luf crystallization..

is a soeeiiie example ot Working in aeoordauee Witln iu;T invention`ille procedure may loo os 'Follows in extraetiuoj sodium eyaoide troni a'turnaee product emitaining` sodiuruV cyanide carbonato eliloride, andon' e (lligure ll The mass is leaelied Witli Wziter at substantially SGO(l. until e. solution saturated with cyanide is obtained.y substantiallyl0() Lorenis ot Water per uns ot cyanide lieinoi used tlien thesaturated solution is filtered and run into suitalalo Cooling' "tanks ormechanical crystaln lith lizers, and cooled to about 100 C. whereuponsubstantially pure sodium cyanide is obtained by crystallization.

It is believed unnecessary to cite other specific examples, as, from thecuryes the procedure in any specific case is evident, it comprising, ingeneral and preferably, leaching with Water at substantially thetemperature of maximum cyanide solubility until a solution saturatedwith cyanide is obtained, and cooling to a lower temperature, takingcare that the ultimate lower temperature is not such as to bring aboutthe throwinglr out ci solution ot the impurities. In cases. that ofcarbonate in 5% hydroxide solution, Figure 2, Where the solubility ofthe carbonate at temperatures intermediate the high temperature, and theultimate low temperature is less than at the latter. the solution may ifdesired be agitated during crystallization to assist' in theredissolving of the carbonate separated at the intermediate temperature.Certain furnace products do not contain impurities in sutlicient amountto saturate the amount of water used. as 100 `frame per 68 of cyanide,but this presents no difficulty as. With solutions with yless impuritiesthan the amount given by the curves, the increasing` solubility ot theimpurities as the temperature decreases, also holds. For maximum yieldat crystallization, it is, ot course, preferable to Work Witha saturatedcyanide solution, buty is not absolutely necessary as, with less thanthe maximum cyanide and more than the minimum impurities, thesolubilities of the impurities increase as the temperature decreases. Iprefer not to use a maximum temperature above 40 (l, and indeed preferto use a temperature somewhat belonT that as. `With Water above about400 C. the cyanide tends to hvdrolyze and be converted into formate andammonia.

ln the commercial practice of the process, the technical manipulationsof the operation may desirably be carried out in any suitably organizedsystem of counter-currentwise leaching apparatus, as for example, asystem o'l' apparatus wherein fresh furnace product, at its point ofentry, meets an almost saturated solution and is linally exhausted bycomingy in contact with pure water. having' traveled against a .currentof decreasingly concentrated solution from the point of entry tothepoint of discharge of the leaching apparatus. In a counter-currentprocess the Water`v of course, is throughout most of its travel,i notsaturated with cyanide and therefore may take up more impurities thanthe saturated solution of cyanide can contain. This merely results inthe impurities being deposited as the cyanide content tends to increase,the dis solving action being selective for cyanide.

The length of time of the leaching operation is dependent on theconcentration of the sodium cyanide in the furnace product, furnaceproducts rich in sodium cyanide and correspondingly lean in sodiumcarbonate, sodium oxide, and .sodium chloride or sodiuniiiuoride. oi:courseA` requiring; less time and nianipulation to obtain the maximumconcentration of sodium cyanide than do products less rich in cyanideand less lean in the other compounds. ln any case, the linally resultinfsaturated solution at the desired temperature is filtered and run intosuitable cooling tanks or mechanical crystallirkzers, and cooled to thetemperature at which substantially l ure sodium cyanide will be obtainedby crystallizatiou` and the, imimrities will remain in the motherliquor. This mother liquor is either diluted with Water and used asmake-up solution for reintroductiou into the leachingr system. or isentered in the leaching system without dilution at a desirable point.

Operating` iu this manner, or a substantially similar manner. With theproi'ier oreanization ot' multiple leaching tanlts and circulating`pumps. the purity of theJ finished product is high-trom 9(399172 aC/nandthe ultimate yield ot finished product is from .SO-% ot the sodiumcyanide present in the original 'furnace product treated. The over-allloss of sodium compounds is lo\y-troin l to l/f ot the sodium coinpoundspresent in the original furnace product-since all Wash Waters andsolutions are returned to the leaching! ein as malte-up solutionsr` andthe only losses are mechanical. or trom handling.

lt will be observed by a study of: the solubility curyes that in certaincases. thc crystallization oilE the cyanide in hydrated form may reducethe Water content of the solution to such an extent that it will nolonger hold in solution all of the impurities present. ln such cases Vitis advisable to compensate for this by addinpr.` to the solution beforecrystallizing. water sullicient to keep the impurities in solution.

The sodium hydroxide is by far the most soluble compound present. andalthough it is usually present in a relatively small amount. it islilely to build up to quite a considerable concentration in the leachingsolutions Where a number ot leaehes of turnace products are necessary tosuflicientlv concentrate the solutions with cyanide for subsequent',crystallization, and also in cases Where mother liquors are used ttormake-up solutions in the further leachingy of `furnace product,since,onaecount o'lits extreme solubility. sodium hydroxide alwayspasses on with. the leach liouor and is always found With the motherliquor after crystallization. It is, therefore, advisable to prevent thecon` centration of sodium hydroxide in the leach ing liquor fromreaching a point. say above loo llf

lWidely 'from the composition ot the ti `recoreiy ot cyanide bycrystallizcation, an

.or Where the niother liquor is not used, ad-

dition ot bicarbonate or carbon dioxide is not called tor. Y

llt will be understood that l may depart product mentioned above, andthat l apply the process to the extraction olf alkali cyanides ingeneral troni other alkali conipounds, and that l inay appl lt to theration ot notassiun'i cyanide i'ronii other potassinin salts or 'tronisodiinn salts, or to the separation ot sodiuni cyanide troni notas sinnior other allc i salts or niiures thereo'li, Without departingr :tronithe :asie invinciples or scono olf the i iention, it being' inerelynecessary to es ablish the inate n'nitual solubilities o'll the systcniin Whichit is de apply thein in the to have ,described above pounds.

,Wise leaching?,I ot JSurnace predial" the character previouslymentioned, to

avoids tbe di iulties inherent in any process that is intermittent .inits operation and 1nvoli'ee costly evaporation ot sol 1tions undernierely the relatiifely inexpensive ci; l,sation ot tl c presentprocess. the

jallilrci i o usly,y cyanide has been dissolved away 'lr .in

the aecon"oanyin,a1 ir" ,u'iti e, thereby leaw ing' the cyanide in sol`v`tion and leaving; the

impurities behind as a residue; in the presont proces cyanide andaccoinpanying` nnpu ies are oi lyon in water, thereby obtaining; a iation o? the cyanide in'ipurities, i'roin which the cyanide is segain apure state by crystallization, leave mgl; the impurities in tbcsolution,`

l claim: Y

lu The process oi" extracting alkali inetal cyanide trein a inasscontaining;` the cyanide and an alkali inetal carbonate, which con-:wists .in leaching the inass with Water at a teinnerature above 350 (l,to dissolve cyanide .and carbonate, cooling; the resulting solution to atenjiperature such that the cya.- nide Will crystallize out and thecarbonate remain in solution, and separating the cyanide crystals fromthe mother liquon 2'. The process of extracting Valkali insta-l cyanidefrom a inass containing the cyanide and an alkali metal carbonate, whichcon sists in leaching` the mass With Water at a temperaturebetweensubstantially 36 and 400 C., to dissolve cyanide and carbonate,cooling; the resulting solution to a temperature such that the cyanidewill crystallize out and the carbonate remain in solution, andseparating the cyanide crystals from the mother liquor. y

fi. The process of extracting alkali metal cyanide :from a inasscontaining the cyanide and an alkali nietal carbonate, which con-y sistsin leacning the inass with Water at a temperature between substantially360 and L00 C. to dissolve cyanide and carbonate, until a solutionsubstantially saturated with cyanide is obtained, cooling the resultingsolution to a temperature such that the cyanide will crystallize out andthe carbonate remain in solution, and separating the cyanido crystalsfrom the mother liquor.

l. rlhe process of extracting alkali nieta] cyanide troni a masscontainingl the cyanide and an alkali metal carbonate, which consists inleaching-the mass with Water at a temperature between substantially 36and l0@ to dissolve cyanide and carbonate, until a solutionsubstantially saturated with cyanide is obtained, cooling the resultingsolution to a temperature between substantially and 0 C., and separatingthe cyanide crystals 'from the mother liquor.

5. rllhe process'ot' extracting` alkali metal cyanide troni a masscontaining the cyanide, an alkali n'ietal carbonate, and an alkali metaloxide, which consists in leaching the mass with Water at a temperaturebetween substantially 360 and a0@ C. to dissolve cyanide and carbonateand convert oxide into hydroxide, until a solution substantiallysaturated With cyanide is obtained, cooling the resulting solution to atemperature such that the cyanide'will crystallize out and the carbonateand hydroxide remain in solution, and separating the cyanide crystalstroni the mother liquor. y

6.` The process of extracting1 alkali nieta] cyanide from a inasscontaining the cyanide, an alkali metal carbonate, and an alkali Inetaloxide, which consists in leaching the inass with Water at a temperaturebetween substantially 36 and 40 C. to dissolve cyanide and carbonate andconvert oxide into hydroxide, until a solution substantially saturatedwith cyanide obtained, cooling1 the resulting solution to a tenipenturebetween substantially 109 and 0O C., and separating the cyanide crystalsfrom the mother liquor.

7. The process of extractingalkali metal cyanide from a mass containingthe cyanide,

anA alkali metal carbonate, an alkali metal oxide, and an alkali metalhalide, which consists in leaching the mass with water at a temperatureabove substantially'19D C. to dissolve cyanide, carbonate and halide,and convert `oxide into hydroxide, cooling the resnlting solution to atemperature such that the cyanide will crystallize out and thecarbonat'e, halide, and` hydroxide remain in selution, and separatingthe cyanide crystals from the Vmother 1i nor.

`8. The process o extracting alkali metal cyanide from a mass containingthe cyanide,

i an alkali metal carbonate, an' alkali metal oxide, and an alkalimeta-l halide, which consists irl leaching the mass with water at atemperature above substantially 19O C. to dissolve cyanide, carbonateand halide, and convert oxide into hydroxide until substantia'lly themaximum concentration of the cyanide is obtained in the resultingsolution, cooling the resulting solution to a temperature such that thecyanide will crystallize out and the carbonate, halide, and hydroxideremain in solution, and separating the cyanide crystals from the motherliquor,

9. The process of extracting alkali metal cyanide from a containing thecyanide, 'an alkali metal carbonate, an alkali metal oxide, and analkali metal halide, which consists in leaching the mass with water at atemperatu're bet'vveen substantially 360 and 400 C; te dissolve cyanide,carbonate and halide, andconv'ert oxidel into hydroxide, until asolution substantially saturated with cyanide is obtained, cooling` theresulting solution to a temperature such that the Vcyanide willcrystallize ont andthe carbonate, halide and hydroxide remain insolution, and separating the cyanide crystals from the mother liquor.

l0. The process of extracting alkali metal cyanide from a masscontaining the cyanide, an alkali metal carbonate, an alkali metaloxide, and an alkali metal halide', which co'nsists in leaching the masswith water at a temperature betxfveen substantially 360 and 40v C. todissolve cyanide, carbonate and halide, an'd convert 'oxide intohydroxide, until a solution substantially saturated with cyanideisobtained, cooling the resulting solution to a teniperature betweensubstantially l0@ and 0 C., and separating the cyanide crystals from themother liquor.

11. The process of extracting alkali metal vcyz'inide fromr a masscontaining the cyanide, analkfili metal carbonate, an alkali metaloxide, and analkali metal fluoride, which consists in leaching the masswith water at atemperature above substantially 19,0 C. to dissolve'cyanide, carbonate and fluoride, and convert oxide into hydroxide,cooling 'the resulting solution to a temperature such that the cyanideWill crystalliz'e out and the carbonate, fluoride, and hydroxide remainin solution, and separating the cyanide crystals from the mother liquor.

l2. The process of extracting alkali metal cyanide from a masscontaining the cyanide, an alkali metal carbonate, an alkali metaloxide, and an alkali metal fluoride, which consists in leaching the masswith water at a temperature above substantially 190 C. to dissolvecyanide, carbonate and fluoride, and convert oxide into hydroxide untilsubstantially the maximum concentration ot' the cyanide is obtained inthe resulting solution, cooling the resulting solution to a temperaturesuch that the cyanide will crystallize out and the carbonate, fluorideand hydroxide remain in solution, and separating the cyanide crystalslirom the mother liquor.

13. The process of extracting alkali metal cyanide from a masscontaining the cyanide, an alkali metal carbonate, an alkali metaloxide, and an alkali metal fluoride, which consists in leaching the masswith water at a temperature between substantially 2lb@ and 400 C. todissolve cyanide, carlmnaie and fluoride, and convert oxide intohydroxide, until a solution substantially saturated with cyanide isobtained. cooling the resulting solution to a temperature such that thecyanide will crystallize ont :1nd the carbonate. liuoride and hydroxideremain in solution, and separating the cyanide crystals from then'iother liquor.

lil. The process oit e.-:.traeting alkali metal cyanide from a masscontaining (he cyanide, an alkali metal carbonate, an alkali metaloxide, and an alkali metal fluoride, which consists in leaching the masswith water at a temperature between substantially 360 and -iOO C. todissolve cyanide, carbonate and fluoride, and convert oxide intohydroxide, until a solution substantially saturated with cyanide isobtained, cooling the resulting solution to a temperature betweensubstantially 10 and OO C., and separating the. cyanide crystals fromthe mother liquor.

l5. The process ot extracting sodium cyanide from a mass containing thecyanide and sodium carbonate, which consists in leaching the mass withwater at a temperaturc above the transition points ot hydrated andanhydrous sodium cyanide. to dissolve cyanide and carbonate, cooling theresulting solution te a temperature such that the eyanide willerystallize out and the carbonate remain in solution, and separating thecyanide crystals from the mother liquor.

16. The process of extracting sodium eyanide from a mass containing thecyanide and sodium carbonate. which consists in leaching the mass withwater at a temperature between substantially 36 and 40 C. to dissolvecyanide and carbonate, cooling the resulting solution to a temperaturesuch that the cyanide will crystallize out and the carbonate remain insolution, and sepa -ating :es/lesse the cyanide Crystals from lshemother liquor. M rlhe proeess of ezdrseiihg sodium ey# snide 'from emess containing the eyehide slid sodiuirl eerhoiiete9 iif'hieh Consistsifo. ll leachingl the moss Wieh Weiter et e lieii'ipere'- ture between.substantially 3Go slid lf/JO C. 'to dissolvecysiiide end eerhoriate,misil s solution suhsteiitielly saturated with ei`- snide is obtained,eooliegv the resiilti soluibioii lo e. temperature sooh that i'he d midewill eryslellize out and the eerooiielne re mein in solution, sindsepsretiiio the eysiiide crystals lf'roiri the mother liqi'ior.

l?. 'lhe proeess ol erfhreetiiig sodium oyl5 snide from s mess omheining`the eyeiiide and sodium carbonate, Whieh eonsists iii leaching the mess'with wir-ler sit o terriperelure between substantially 360 end l0@ C.to dissolve cyanide und eerhemiley ehl'il a solution substantiallyseiireled Wii'ih eyeiiide is olotsineeh eooliiig the resihI ing solotionto e, tslope-leisure between embellirtielly 10o slid 0O C., eedYseoereliiig ille l. eysieide erystels from elle` moli/her liquor:

19. The process olf eirtrseliiig sodium eyenide 'from e mass oonleiningthe oyeieide7 sodium esi-bollate ered sodium o1, Whieh eoiisists iiilese/hing `the iifirh ter ne e teiiipersture between silissiilzielly 350slid ll()O C. lo dissolve eysnide :md esrlioiislie sud couvert oxideinto hydroxide, iiiiil sehrtioii siiibsteli'liislly saturated withCyanide is obtained, Cooling lzhe i lieg; sel ori lo e teiripereturesuoli thee Vthe ejeiiide will eryslellirze out und the esrluorisle zuidl dreizide remain in solution, end separe the Cyanide Crystals 'from thereeel liqiiofg'. 20. The process el' extracting sod o eye-- Iride frommess containing lihe i" lll sodium esrlioiiste, :uid sodium o;

consists iii leaching the mess with ii s, leiiipereture helgweensiilisleii'tiel. ello eed d0" to dissolve eysiiide end omflfmelie eedconvert oxide inte hydroxide, until e soloi5 'sion siihsisiitiellyseturzited with eyenide oli'lpeined, ooolin the resi lining solution see temperature lieibweee lzislljy l0@ end O0 C., and separating J[hecyanide eryslesls ifi-ore she mother liquor; i i

The process olf exhausting sodium eye.. eide :from s` hiesseeii"'"'1'iiiig; l'he oyeeide, sodi,A 'i eerhonerej e ui oxide sedsodium halide, which Consists in lesohihg `ehe m with waiter el e`temilierelmre ehoiiesiihslieo- 55 tisllj/ lflo C. lao dissolveevfiiiide, om' a" 'end halidel and Convert oxide loro hyd A, ide,eeoliegl Athe resulting; solution te e telopereore such lhot the eyeeidewill Crystallize out sind the eoroonel'e9 halide eed l droxide remainiii solution, end separe the cyanide crystals liro'o'l the iooherliquor. y .92. The process of esiti-noting eedie'ei e eide 'from s`hiess eoii'teiiiiiip; the cyanidel .sodiumcerbonsle, Asodium oxide andsodium l@ lielide, which consists in leaching 'the mess hjivdrof-:ideremain insolution, and seperatwith Weler el; e tempersture shove sohslsnitislly 19o l) to dissolve {5j/snide7 carbonate and hslideJ sodeoi'ivert of 'd hito hydro? e welll substantially lhe il' i im eeiiee'tion oli' the eil-snide is ol;Uk hed iii die resi ing solvlieiiqeooliiio lhe resolihe stsiitielly 860 sied l- OAO 15o d soy ein iride,carbonate eiid halide, eed ooey o'fide into hydroiride, until o solutionsol,- s'liehlzislly saturate-d eflh eyseide is oh "mined cooling; theresulting solulnioii fao s lemperelure suoli that he cyanide will erAlmllir/ie eel; end 'the eerhoiis'te, halide eed hydroxide ree-min iiisolution, :md sepsrolm ino; *she eysiiide Crystals from 'the reolwer l?.liquorn The proeess oil @directing sodium e312 hide from e. i sseenleining; the cyanidea sodium eerhoiieee, sod'eiri oxide9 sind sodiumhelide7 which oonsisss iii leeehihg "the mess willi Weiber el: :itempersisre between seh slenlielly 3Go amd lello to dissolve eyeiiide.,eerheneite mid holide :md eeiiiv'erl; oxiee into liiydroxide, metil esolo ion suhslszinlielly l. setuii'eled with cyanide is obtained9cooling il 'the reselling solution to e iteiiipersture he lief'eensuhssellielly l0@ eed 0 C., sind. sepereihig; 'lhe `Cyanide oryslgsls'from the mother lisser.

The preeess ol extracting sodium eyeiiide from :i mess containing' theeyeiiide., si es i'lieesle9 sodium oxiden sind sodium Y fide, whichconsists iii leeeliiiig llLhe mess With Welter e 'len'lperetm'e shovesiihstsiilslljgf 190 ll. lo dissolve cyanide, eerhonste n d Fluoride7end Convert oxide into hydroxide7 eooliiio; the reselling solution lo ekempeinture siieh that the cyanide Will Crystal lise out :me theeerhoiisfte, fluoride :md

llO

iep; the ejisiiide Crystals from 'lelie mother liquor.

The posees-i of ex'lerseling; sodiulri eye eide il ein :i messcontaining; Ythe Cyanide, sod' i oerhonelze, sodium oxide sind sodiumfluoride, which Consists in leaching' lille mess with waiter el; :iteiiipereture shove sul3- sleetislly lll@ C. lo dissolve cyanide,eerhoiiele sind Querido', and eoiivert ox.` le into hydroxide, until silsiitielly 'the maximum. eoiieeii'lrelioii olE the oyiieide is obtainedin VThe reselling sohiioii, cooling); Jshe resulting solution to e'temperature sueh that the eyeiiide will orystellize out and -thecarbonate, iluoride and hydroxide remain iii solorzien2 and separatingthe cyanide crystals from the mother liquor.

2T. The process of ellractiug sodium cyanide from a mass containing thecyanide, sodium carbonate, sodium oxide, and sodium fluoride, whichconsists in leaching the mass with water at a temperature between sub--stantially o6@ and 400 C. to dissolve cyanide, carbonate and fluoride,and convert oxide into hydroxide, until a solution substantiallysaturated with cyanide is obtained, cooling the resulting solution to atemperature such that the cyanide will crystallize out and thecarbonate, fluoride and hydroxide remain in solution, and separatii'igthe cyanide crystals from 'the mother liquor.

28. The process of extracting sodium cyanide from a mass containing thecyanide, sodium carbonate, andv sodium oxide, and

sodium lluoride,'which consists in leaching he mass with water at atemperature between substantially 3Go and 40 C. to dissolve cyanide,carbonate and fluoride, and convert oxide into hydroxide, until asolution substantially saturated with cyanide is obtained, cooling theresulting solution to a temperature between substantially 10 and GO C.,and separating the cyanide crystals from the mother' liquor.

29. The process of extracting alkali metal cyanide from a masscontaining the cyanide and an alkli metal carbonate, which consists inleaching Vthe mass with water at. a temperature above substantially 190C. to dissolve cyanide and carbonate, adding water to compensate forwater that will be removed from the solution by crystallization ofcyanide in hydrated form, cooling the resulting solution to atemperature such that the cyanide will crystallize out and the carbonateremain in solution, and separating the cyanide crystals from the motherliquor. Y

30. `The continuous process' of extracting alkali metal cyanide frommasses containing the cyanide and' an alkali metal carbonate, whichconsists in leaching masses of successively increasing cyanide strengthwith a current of water at a temperature abovev substantially 19 C. andflowing in the direction of increasing cyanide strength in the masses,vto dissolve the cyanide and carbonate, coolingl the solution flowingfrom a mass of relatively greater cyanide strength to a temperature suchthat the cyanide will crystallize out and the carbonate remain insolution, separating the cyanide crystals from the mother liquor,returning the liquor to the system and to a mass of relatively lessercyanide strength, and repeating the various saidv steps.

31. The continuous process of extracting Aalkali metal cyanide frommasses containing the' cyanide, an alkali metal? carbonate, and

an alkali metal oxide, which consists in leachi gj masses otsuccessively' increasing cyanide strength with a current ol' water at atemperature above substantiallyY lll" (l. and flowing in the directionot incieasing cyanide strength in the masses, to dissolve -the cyanideand carbonate, and Iconvert the oxide into hydroxide, cooling thesolution flowing liroin a niass of relatively greater cyanide strengthto a temperature such that the cyanide will crystalline out and thecarbonate and hydroxide remain in solution, separating the cyanidecrystals from the mother liquor, converting a portion ot' the hydroxideinto carbonate, returning the lii ir to the systen'i and to a mass ofrelinel the various said steps.

atively lesser cyanide strength, and repeat- The continuousprocess otextracting ,i metal cyanide from masses containthe cyanide, an all-:alimetal carbonate, and an alkali metal oxide, which consists in leaching.masses of successively increascyanide strength with a current ol waterat a temperature above substantially 190 C. and vflowing in thedirection of increasj cyanide strength in the masses, to dissol i. e thecyanide and carbonate, and convert the oxide into hydroxide, cooling thesolution flowing troni a mass ot relatively lgreater cyanide strength toa temperature auch thatA the cyanide will crystalline out and thecarbonate and hydroxide remain in solution, separating the cyanidecrystals i'rom the mother liquor, adding sodium bicarbonate to theliquor to convert a portion of the hydroxide into carbonate, returningthe liquor to the system and to a mass ot relatively lesser cyanidestrength, and repeating the various saidv steps.

33. rlhe process oi producing a solution rich in alliali metal cyanidefrom a mass containing the cyanide and an alkali metal carbonate, whichcomprises leaching said mass with water at a temperature of 'from about36 to 400 C.

3l. The process ot producing a solution rich in alkali metal cyanide andpoor in alkali metal carbonate from a mass containing said cyanide andalkali metal carbonate, which comprises leaching said mass with water ata temperature between about 3G and 400 C.

85. The process of producingr a solution rich in alkali metal cyanidefrom a mass containing said cyanide, an alkali metal carbonate and anall-tali metal oxide, which comprises leaching said mass at atemperature bet veen about 3G and 400 C. with water which is initiallysubstantially tree lfrom alkali metal bicarbonate 36. The process ofextracting sodium cyanide from a mass containing sodium cyanide andsodium carbonate, which conilill prises leachingsaid-mass with water ata temperature above tile transition points of hydrated and anhydroussodium cyanide.

37. 'ilhe process of extracting sodium cyanide 'from a mass containingsodium cyanide, sodium carbonate, and sodium oxide, which comprisesleaching said mass at a temperature between 36 and L00 C. with Waterwhich is initially substantially free 'from sodium bicarbonate.

38. The process of extracting sodium cyanide from a mass containingsodium cyanide, sodiuin carlmnateJ a sodium halide, and sodium oxide,which comprises leaching` said rnass at a temperature between 30 and 40C. with Water which is initially substantially free from sodiumbicarbonate.

In testimony whereof l affix my signature.

CHARLES B. JACOBS.

